Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Study on Fatigue Life Estimation for Aircraft Engine Support Structure

항공기 엔진 지지구조물의 피로수명 해석에 관한 연구

  • Hur, Jang-Wook (KHP PMO, Defense Acquisition Program Administration)
  • Received : 2010.05.31
  • Accepted : 2010.09.04
  • Published : 2010.11.01
Download PDF
⟨ Previous Next ⟩

Abstract

The fatigue life is estimated while determining the reliability of aircraft structures. In this study, the estimation of fatigue life was carried out on the basis of a cumulative damage theory; the working S-N curve and the equivalent stress on the engine support structure significantly affect the safety of the aircraft. The maximum stress observed was 1,080 MPa in the case of scissors link under crash load condition, and there was a 5% margin for the allowable stress corresponding to the temperature reduction factor. The maximum stress was 876 MPa, and the stress equation coefficient had a maximum value of 0.019 MPa/N in the case of scissors link under fatigue loads. In the results of the fatigue life analysis, the safety life in a fretting area of scissors link upper part was 416,667 flight hour, and other parts showed to infinite life. Therefore, it was demonstrated that the fatigue life requirement of aircraft engine support structure (scissors link, straight link) could be satisfied.

항공기 구조는 신뢰성 보장을 위해 피로하중에 대한 수명예측이 중요한 분야로 고려되고 있다. 본 논문에서는 항공기 비행안전과 가장 밀접한 엔진 지지구조물을 대상으로 S-N 곡선과 등가응력을 이용하여 선형누적손상 이론을 적용한 피로수명 해석을 수행하였다. 내추락 하중 조건에서 정적강도 해석의 최대응력은 가위형 링크 부위에 1,080MPa를 나타내었으며, 이는 온도감소계수를 적용한 허용응력보다 약 5%의 여유를 가지고 있다. 피로하중 조건에서 최대응력은 가위형 링크 부위에 876MPa로 가장 높았으며, 이 때 응력방정식 계수도 0.019MPa/N으로 최대를 나타내었다. 피로수명 해석에 의한 안전수명은 가위형 링크 상단부에 있는 프레팅 영역이 416,667H이고, 다른 부위는 무한수명이 산출되어, 항공기 엔진 지지구조물(가위형 링크, 직선형 링크)은 피로수명 요구도를 충족하는 것으로 확인되었다.

Keywords

References

  1. Baek, S. H., Cho, S. S., Kim, H. S. and Joo, W. S., 2009, "Reliability Design of Preventive Maintenance Schedule for Cumulative Fatigue Damage," Journal of Mechanical Science and Technology, Vol. 23, pp. 1225-1233. https://doi.org/10.1007/s12206-008-0901-z
  2. Shin, K. S., 2009, "Prediction of Fretting Fatigue Behavior Under Elastic-Plastic Conditions," Journal of Mechanical Science and Technology, Vol. 23, pp. 2714-2721. https://doi.org/10.1007/s12206-009-0723-7
  3. Lee, D. H., Kwon, A. J., You, W. H., Choi, J. B. and Kim, Y. J., 2009, "Evaluation of Fatigue Crack Initiation Life in a Press-Fitted Shaft Considering the Fretting Wear," Journal of the KSME, Vol. 33, pp. 1091-1098.
  4. Cho, J. U. and Han, M. S., 2009, "Study on Fatigue at Disk Brake," Transaction of the Koran Society of Machine Tool Engineers, Vol. 18, pp. 201-206.
  5. Kwon, J. H., 1994, "Fatigue Life Evaluation of Carry-thru Beam Structure of Small Aircraft under Flight-by-Flight Load Spectrum," Korea Aerospace University, pp. 63-71.
  6. Bannantine, J. A., Comer, J. and Handrock, J., 1990, Fundamentals of Metal Fatigue Analysis, Prentice Hall, pp. 6-15.
  7. Eurocopter, 2006, Methodology for the Fatigue Substantiation of the Mechanical Components and Airframe, KHP project, TTK005A0027E01A, pp. 64-71.
  8. Christian, L., 1999, Mechanical Vibration & Shock : Fatigue Damage, Hermes Science Publications, pp 100-108.
  9. USA DOD, 1998, Metallic Materials and Elements for Aerospace Vehicle Structure, MIL-HDBK-5H, pp. 2-152-2-159.
  10. USA DOD, 1988, Light Fixed and Rotary- Wing Aircraft Crash Resistance, MIL-STD-1290A, pp. 6-23.

Cited by

  1. Stress Spectrum Algorithm Development for Fatigue Crack Growth Analysis and Experiment for Aircraft Wing Structure vol.39, pp.12, 2015, https://doi.org/10.3795/KSME-A.2015.39.12.1281